The following websites are helpful resources that provide information on developmental norms for speech and language, as well as the various speech-language disorder categories.
 
 

Developmental Norms for Speech and Language
Find out what skills are expected to develop at what ages.

Speech & Language Development
Outlined here are the various ages and stages of speech and language development and what you should expect with your child.

Speech vs. Language
Learn the differences between speech and language.

Speech Sound Acquisition
Look here to see when specific speech sounds develop and when you can expect your child to master certain speech sounds.

How to Play
Tips and ideas for effective ways to play with your child.

Communicating with a 2-3 Year Old
Ways to communicate with your toddler, vocabulary and communication patterns, typical communication problems and what to do if one is suspected.

Learning Language
An overview of language development, learning language, speech and language milestones, what's typical and what's not

Ages & Stages of Language Development Birth-Five
Expected language milestones for children ages birth-five